On the cusp form motives in genus 1 and level 1

Abstract

We prove that the moduli space of stable n-pointed curves of genus one and the projector associated to the alternating representation of the symmetric group on n letters define (for n>1) the Chow motive corresponding to cusp forms of weight n+1 for SL(2,Z). This provides an alternative (in level one) to the construction of Scholl.

18 pages. To appear in Moduli Spaces and Arithmetic Geometry, Advanced Studies in Pure Mathematics, 2006